Allogeneic Hematopoietic Stem Cell Transplantation for Adolescents and Young Adults with Acute Myeloid Leukemia

Rare event approximation between subdistribution hazard ratio and cause-specific hazard ratio in survival analysis with competing risks

BackgroundDespite the fact that competing risks are inevitable in epidemiological and clinical studies, distinctions between the hazard ratio estimated by handling competing risks as censoring and the subditribution hazard ratio are often overlooked.MethodsWe derive quantitative relationships between subdistribution hazard ratio and cause-specific hazard ratio, and derive an approximate calculation method to transform the two into each other. Numerical examinations of hypothetical six scenarios and published information of a randomized clinical trial of cholesterol-lowering therapy and a registry of acute myeloid leukemia were provided.ResultsGeneral and approximate relationships under rare event assumptions between the two types of hazard ratio were given. The approximation formula is based on a survival ratio and has two possible applications. First, one can calculate a subdistribution hazard ratio from published information. Second, this formula allows sample size estimation that takes the presence of competing risks into account.ConclusionsThe distinction between the two types of hazard ratio can be addressed by focusing on two quantities. One is how the event of interest and competing risk is rare, and the other is the survival ratio.

Survival difference between secondary and de novo acute myeloid leukemia by age, antecedent cancer types, and chemotherapy receipt

BACKGROUND

This study compared the survival of persons with secondary acute myeloid leukemia (sAML) to those with de novo AML (dnAML) by age at AML diagnosis, chemotherapy receipt, and cancer type preceding sAML diagnosis.

METHODS

Data from Surveillance, Epidemiology, and End Results 17 Registries were used, which included 47,704 individuals diagnosed with AML between 2001 and 2018. Multivariable Cox proportional hazards regression was used to compare AML-specific survival between sAML and dnAML. Trends in 5-year age-standardized relative survival were examined via the Joinpoint survival model.

RESULTS

Overall, individuals with sAML had an 8% higher risk of dying from AML (hazard ratio [HR], 1.08; 95% confidence interval [CI], 1.05-1.11) compared to those with dnAML. Disparities widened with younger age at diagnosis, particularly in those who received chemotherapy for AML (HR, 1.14; 95% CI, 1.10-1.19). In persons aged 20-64 years and who received chemotherapy, HRs were greatest for those with antecedent myelodysplastic syndrome (HR, 2.04; 95% CI, 1.83-2.28), ovarian cancer (HR, 1.91; 95% CI, 1.19-3.08), head and neck cancer (HR, 1.55; 95% CI, 1.02-2.36), leukemia (HR, 1.45; 95% CI, 1.12-1.89), and non-Hodgkin lymphoma (HR, 1.42; 95% CI, 1.20-1.69). Among those aged ≥65 years and who received chemotherapy, HRs were highest for those with antecedent cervical cancer (HR, 2.42; 95% CI, 1.15-5.10) and myelodysplastic syndrome (HR, 1.28; 95% CI, 1.19-1.38). The 5-year relative survival improved 0.3% per year for sAML slower than 0.86% per year for dnAML. Consequently, the survival gap widened from 7.2% (95% CI, 5.4%-9.0%) during the period 2001-2003 to 14.3% (95% CI, 12.8%-15.8%) during the period 2012-2014.

CONCLUSIONS

Significant survival disparities exist between sAML and dnAML on the basis of age at diagnosis, chemotherapy receipt, and antecedent cancer, which highlights opportunities to improve outcomes among those diagnosed with sAML.

Allogeneic hematopoietic stem cell transplantation for adults with therapy-related acute myeloid leukaemia: a retrospective multicentre study on behalf of the SFGM-TC

We report the results from a multicentre retrospective study of 220 adult patients who underwent allogeneic hematopoietic stem cell transplantation (alloHSCT) for therapy-related acute myeloid leukaemia (t-AML). Median age at t-AML diagnosis was 56 years, with a prior history of haematological (45%) or breast (34%). Median time from cytotoxic exposure to t-AML diagnosis was 54.7 months. At transplant, around 20% of patients had measurable residual disease and 3% of patients were not in complete remission. The median follow-up was 21.4 months (Q1-Q3, 5.9-52.8). At 12 months, overall survival (OS), event-free survival (EFS), and graft-versus-host-disease (GVHD)-free-relapse-free survival (GRFS) were 60.7% (95% CI 54.6-67.5), 52.8% (95% CI 46.5-68.4), and 44.1% (95% CI 37.6-51.8), respectively. At 5 years, OS, EFS, and GRFS were 44.1% (95% CI 37.4-52.1), 40.4% (95% CI 33.9-48.1), and 35.3% (95% CI 28.8-43.3), respectively. At last follow-up, 44% of patients were in complete remission (n = 96) and transplant-related mortality accounted for 21% of all deaths (n = 119). Multivariable analysis revealed that uncontrolled t-AML at transplant was associated with lower EFS (HR 1.94, 95% CI 1.0-3.7, p = 0.041). In conclusion, alloHSCT for t-AML shows encouraging results and offers additional opportunity with the emergence of novel pre-graft therapies.

Outcomes of haploidentical haematopoietic stem cell transplantation for adolescent and young adults with acute myeloid leukaemia

We aimed to identify the efficacy of haploidentical related donor (HID) haematopoietic stem cell transplantation (HSCT) in adolescent and young adults (AYAs) with acute myeloid leukaemia (AML) in a large cohort. Consecutive AML AYAs (15-39 years old, n = 599) receiving HID HSCT in complete remission (CR) were included. The 3-year cumulative incidence of measurable residual disease occurrence, relapse and non-relapse mortality after HID HSCT was 28.6% (95% CI: 25.0-32.2), 11.6% (95% CI: 9.0-14.2) and 6.7% (95% CI: 4.7-8.7) respectively. The 3-year probability of event-free survival, leukaemia-free survival (LFS) and overall survival (OS) after HID HSCT was 60.7% (95% CI: 56.9-64.8), 81.7% (95% CI: 78.7-84.9) and 85.6% (95% CI: 82.8-88.4) respectively. In multivariable analysis, AML risk category at diagnosis and comorbidity burdens before HID HSCT were independently associated with LFS and OS. Compared to the older adults (≥ 40 years, n = 355) with AML receiving HID HSCT in CR during the same time period, AYAs have a lower incidence of non-relapse mortality and higher probabilities of LFS and OS. Thus, we firstly confirmed the safety and efficacy of HID HSCT in AYAs with AML-CR.

Adapting the HCT-CI Definitions for Children, Adolescents, and Young Adults with Hematologic Malignancies Undergoing Allogeneic Hematopoietic Cell Transplantation

Allogeneic hematopoietic cell transplantation is a curative procedure for hematologic malignancies but is associated with a significant risk of non-relapse mortality (NRM). The Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) is a prognostic tool that discriminates this risk in all age groups. A recent survey of transplant physicians demonstrated that 79% of pediatric providers used the HCT-CI infrequently, and most reported concerns about its applicability in the younger population. We conducted a retrospective study using the Center for International Blood and Marrow Transplant Research database to examine the impact of expanded HCT-CI definitions on NRM in pediatric and young adult patients with hematologic malignancies. We included 5790 patients <40 years old receiving allogeneic transplants between 2008 and 2017 to examine broader definitions of comorbidities in the HCT-CI, including history of mechanical ventilation and fungal infection, estimated glomerular filtration rate, and body mass index (BMI) percentiles. Multivariable Fine-Gray models were created to determine the effect of each HCT-CI defining comorbidity and its modification on NRM and were used to develop 2 novel risk scores. We next developed the expanded HCT-CI for children and young adults (youth with malignancies; expanded ymHCT-CI), where 23% patients had an increased comorbidity score, compared to the HCT-CI. Comorbidities with hazard ratio < 1.2 were then removed to create the simplified HCT-CI for children and young adults (youth with malignancies; simplified ymHCT-CI), which demonstrated higher scores corresponded to a greater risk of NRM (P < .001). These novel comorbidity indexes with broader definitions are more relevant to pediatric and young adult patients, and prospective studies are needed to validate these in the younger patient population. It remains to be seen whether the development of these pediatric-specific and practical risk indexes increases their use by the pediatric transplant community.

Adolescents and young adults (AYA) with acute myeloid leukemia (AML): real-world long-term results and age-specific outcomes

Opposing acute lymphoblastic leukemia, sparse data about AYAs with acute myeloid leukemia (AML) is available. Overall, 125 AYAs (age 10-35 years) treated during the last two decades were evaluated and compared to 385 older patients. CBF leukemia was more frequent in AYAs (21.6% vs. 8%, p < 0.001); however, many presented high-risk features. AYAs showed improved complete remission rate (CR, 80% vs. 65%, p = 0.01), lower cumulative incidence of relapse and TRM and longer survival (5 year-OS 53% vs. 24%, p < 0.0001), observed mainly in intermediate-risk karyotype. Adolescents displayed even better outcomes (5 year-OS 69%). AlloHCT in CR1 was beneficial for nonadolescent AYAs (5 year-OS 66.7% vs. 44.4% without HCT, p = 0.04). Among 50 APL patients, 19 AYAs experienced better outcomes than older, mainly attributed to reduced treatment-related mortality (TRM, 5% vs. 19%, p = 0.1). We observed an important (>10%) survival gain for AYAs during the last decade. However, AYAs have still unmet needs to obtain optimal cure rates.

Mapping the Landscape of Advance Care Planning in Adolescents and Young Adults Receiving Allogeneic Hematopoietic Stem Cell Transplantation: A 5-Year Retrospective Review

Allogeneic hematopoietic stem cell transplantation (HSCT) carries significant risks of morbidity and mortality. Participation in advance care planning (ACP) is crucial to promote patient-centered care and has been shown to have positive impacts on patients, caregivers, and providers. Historically, both HSCT recipients and adolescents and young adults (AYAs) are significantly less likely to engage in ACP. We sought to characterize ACP utilization in AYAs undergoing HSCT by evaluating the frequency of different types of ACP documentation over time and identifying demographic and clinical factors associated with documentation of each type of ACP. We conducted a single-center retrospective review of the electronic health record (EHR) of AYAs (age 15 to 39 years) who underwent allogeneic HSCT between 2015 and 2020. EHR documents were screened for 3 predefined categories of ACP: (1) advance directives (ADs) or medical orders (MOs), which included proof of signed paper directives, expressions of preferred code status, and identification of a healthcare proxy; (2) goals of care (GOC) conversations, which included discussions of medical care in a specific situation informed by patients' priorities; and (3) other ACP conversations, which included more general discussions of patients' values regarding their care or legacy wishes. Documents were coded by 2 researchers, and discrepant categorizations were reviewed by a third researcher. Patients age <18 years on the day of transplantation were excluded in the analyses of AD/MO documentation. Univariate and multivariate logistic regression were used to test for associations between patient factors and documentation of each type of ACP. For deceased patients, Kaplan-Meier curves were created to illustrate the time-to-event relationship between days before death and documentation of each type of ACP. Sixty-eight thousand documents associated with 219 patients were reviewed, and 666 ACP documents associated with 190 patients were identified. Few of the 219 patients had documented GOC (n = 29; 13%) or other ACP conversations (n = 81; 37%). A subset of patients (n = 28; 13%) had no documented ACP. Most of the 201 patients age ≥18 years had a documented AD/MO (n = 172; 86%). No tested factors were significantly associated with documentation of ADs/MOs. GOC and other ACP conversations were more likely to occur in patients with a palliative care consult, and patients with a malignant diagnosis were also more likely to engage in GOC conversations. More than 50% of the documentation occurred in the subset of 39 deceased patients, with one-half of AD/MO documentation in the last 67 days of life, one-half of other ACP documentation in the last 20 days of life, and one-half of GOC documentation in the final 2 days of life. Although the majority of AYA patients receiving HSCT did have documentation of ADs/MOs, few patients had documented GOC or other ACP conversations. The bulk of all ACP conversations occurred in patients that ultimately died and who were very close to the end of life. Our results support ongoing efforts to improve the implementation of ACP in this vulnerable population, particularly for those undergoing HSCT for nonmalignant conditions.

Improved outcome in children compared to adolescents and young adults after allogeneic hematopoietic stem cell transplant for acute myeloid leukemia: a retrospective study from the Francophone Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC)

Background

There are currently few data on the outcome of acute myeloid leukemia (AML) in adolescents after allogeneic HSCT. The aim of this study is to describe the outcome and its specific risk factors for children, adolescents and young adults after a first allogeneic HSCT for AML.

Methods

In this retrospective study, we compared the outcome of AML patients receiving a first allogeneic HSCT between 2005 and 2017 according to their age at transplantation’s time: children (< 15 years, n = 564), adolescent and post-adolescent (APA) patients (15–25 years, n = 647) and young adults (26–40 years; n = 1434).

Results

With a median follow-up of 4.37 years (min–max 0.18–14.73 years), the probability of 2-year overall survival (OS) was 71.4% in children, 61.1% in APA patients and 62.9% in young adults (p = 0.0009 for intergroup difference). Both relapse and non-relapse mortality (NRM) Cumulative Incidence (CI) estimated at 2 years were different between the age groups (30.8% for children, 35.2% for APA patients and 29.4% for young adults—p = 0.0254, and 7.0% for children, 10.6% for APA patients and 14.2% for young adults, p < 0.0001; respectively). Whilst there was no difference between the three groups for grade I to IV acute GVHD CI at 3 months, the chronic GVHD CI at 2 years was higher in APA patients and young adults (31.4% and 36.4%, respectively) in comparison to the children (17.5%) (p < 0.0001). In multivariable analysis, factors associated with death were AML cytogenetics (HR1.73 [1.29–2.32] for intermediate risk 1, HR 1.50 [1.13–2.01] for intermediate risk 2, HR 2.22 [1.70–2.89] for high cytogenetics risk compared to low risk), use of TBI ≥ 8 Grays (HR 1.33 [1.09–1.61]), disease status at transplant (HR 1.40 [1.10–1.78] for second Complete Remission (CR), HR 2.26 [1.02–4.98] for third CR and HR 3.07 [2.44–3.85] for active disease, compared to first CR), graft source (HR 1.26 [1.05–1.50] for Peripheral Blood Stem Cells compared to Bone Marrow) and donor age (HR 1.01 (1–1.02] by increase of 1 year).

Conclusion

Age is an independent risk factor for NRM and extensive chronic GVHD. This study suggests that APA patients with AML could be beneficially treated with a chemotherapy-based MAC regimen and bone marrow as a stem cells source.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03761-w.

Beyond steroids: A systematic review and proposed solutions to managing acute graft-versus-host disease in adolescents and young adults

The outcomes of allogeneic hematopoietic cell transplantation (HCT) in adolescents and young adults (AYAs) with hematologic malignancies have been shown to be poorer when compared to results in children, due to a combination of higher relapse rates and greater treatment-related mortality (TRM). Although differences in relapse risk have been studied extensively, toxicity has been examined and reported less often. In this systematic review, we summarize recently published studies that have examined the differences in rates of TRM and acute graft-versus-host disease (GVHD) in AYAs and children with hematologic malignancies, and attempt to explain why these disparities exist and how they impact outcomes. In addition, we present best practices for management of steroid-refractory GVHD that are likely to improve survival in this patient population. Further, we propose the development of personalized, risk-based approaches for the prevention and treatment of GVHD that incorporate novel platforms and interventions. We believe this individualized approach is likely to reduce toxicity and greatly improve outcomes for this vulnerable population.

Allogeneic hematopoietic stem cell transplantation for myelodysplastic syndrome in adolescent and young adult patients

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curable treatment option for adolescent and young adult (AYA) patients with myelodysplastic syndrome (MDS). The study aim was to evaluate epidemiological data and identify prognostic factors for AYA patients with MDS undergoing allogeneic HSCT. Here, 645 patients were selected from patients enrolled in a multicenter prospective registry for HSCT from 2000 to 2015. The primary endpoint was 3-year overall survival (OS). Survival rates were estimated using the Kaplan-Meier method. Prognostic factors were identified using the multivariable Cox proportional hazards model. The 3-year OS was 71.2% (95% confidence interval [CI]: 67.4-74.6%). In multivariable analysis, active disease status (adjusted hazard ratio: 1.54, 95% CI: 1.09-2.18, p = 0.016), poor cytogenetic risk (1.62, 1.12-2.36, p = 0.011), poor performance status (2.01, 1.13-3.56, p = 0.016), human leukocyte antigen (HLA)-matched unrelated donors (2.23, 1.39-3.59, p < 0.001), HLA-mismatched unrelated donors (2.16, 1.09-4.28, p = 0.027), and cord blood transplantation (2.44, 1.43-4.17, p = 0.001) were significantly associated with poor 3-year OS. In conclusion, in AYA patients with MDS the 3-year OS following allogeneic HSCT was 71.2%. Active disease status, poor cytogenetic risk, poor performance status, and donor sources other than related donors were associated with poor 3-year OS.

Late effects after ablative allogeneic stem cell transplantation for adolescent and young adult acute myeloid leukemia

There is marked paucity of data regarding late effects in adolescents and young adults (AYAs) who undergo myeloablative conditioning (MAC) allogeneic hematopoietic cell transplantation (HCT) for acute myeloid leukemia (AML). We evaluated late effects and survival in 826 1-year disease-free survivors of MAC HCT for AYA AML, with an additional focus on comparing late effects based upon MAC type (total body irradiation [TBI] vs high-dose chemotherapy only). The estimated 10-year cumulative incidence of subsequent neoplasms was 4% (95% confidence interval [CI], 2%-6%); 10-year cumulative incidence of nonmalignant late effects included gonadal dysfunction (10%; 95% CI, 8%-13%), cataracts (10%; 95% CI, 7%-13%), avascular necrosis (8%; 95% CI, 5%-10%), diabetes mellitus (5%; 95% CI, 3%-7%), and hypothyroidism (3%; 95% CI, 2%-5%). Receipt of TBI was independently associated with a higher risk of cataracts only (hazard ratio [HR], 4.98; P < .0001) whereas chronic graft-versus-host disease (cGVHD) was associated with an increased risk of cataracts (HR, 3.22; P = .0006), avascular necrosis (HR, 2.49; P = .006), and diabetes mellitus (HR, 3.36; P = .03). Estimated 10-year overall survival and leukemia-free survival were 73% and 70%, respectively, and did not differ on the basis of conditioning type. In conclusion, late effects among survivors of MAC HCT for AYA AML are frequent and are more closely linked to cGVHD than type of conditioning.

Prognostic Value of MicroRNA-20b in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a highly heterogeneous disease that requires fine-grained risk stratification for the best prognosis of patients. As a class of small non-coding RNAs with important biological functions, microRNAs play a crucial role in the pathogenesis of AML. To assess the prognostic impact of miR-20b on AML in the presence of other clinical and molecular factors, we screened 90 AML patients receiving chemotherapy only and 74 also undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) from the Cancer Genome Atlas (TCGA) database. In the chemotherapy-only group, high miR-20b expression subgroup had shorter event-free survival (EFS) and overall survival (OS, both P < 0.001); whereas, there were no significant differences in EFS and OS between high and low expression subgroups in the allo-HSCT group. Then we divided all patients into high and low expression groups based on median miR-20b expression level. In the high expression group, patients treated with allo-HSCT had longer EFS and OS than those with chemotherapy alone (both P < 0.01); however, there were no significant differences in EFS and OS between different treatment subgroups in the low expression group. Further analysis showed that miR-20b was negatively correlated with genes in “ribosome,” “myeloid leukocyte mediated immunity,” and “DNA replication” signaling pathways. ORAI2, the gene with the strongest correlation with miR-20b, also had significant prognostic value in patients undergoing chemotherapy but not in the allo-HSCT group. In conclusion, our findings suggest that high miR-20b expression is a poor prognostic indicator for AML, but allo-HSCT may override its prognostic impact.

Allogeneic Hematopoietic Cell Transplantation for Adolescent and Young Adult Patients with Acute Myeloid Leukemia

Limited data exist regarding the outcomes of allogeneic hematopoietic cell transplantation (allo-HCT) among adolescent and young adult (AYA) patients with acute myeloid leukemia (AML). Here we analyzed the features and outcomes of AYA patients with AML who had achieved complete remission (CR) and those who had not (non-CR) at allo-HCT. We retrospectively analyzed 2350 AYA patients with AML who underwent allo-HCT with a myeloablative conditioning regimen and who were consecutively enrolled in the Japanese nationwide HCT registry. The difference in overall survival (OS) between younger (age 16 to 29 years) and older AYA (age 30 to 39 years) patients in CR at transplantation was not significant (70.2% versus 71.7% at 3 years; P = .62). Meanwhile, this difference trended toward a statistical significance between younger and older AYA patients in non-CR at transplantation (39.5% versus 34.3% at 3 years; P = .052). In AYA patients in CR and non-CR, the age at transplantation did not affect relapse or nonrelapse mortality (NRM). In AYA patients in CR, no difference in OS was observed between those who received total body irradiation (TBI) and those who did not (71.1% versus 70.5% at 3 years; P = .43). AYA patients who received TBI-based conditioning had a significantly lower relapse rate and higher NRM than those who underwent non-TBI-based conditioning (relapse: 19.8% versus 24.1% at 3 years [P = .047]; NRM: 14.7% versus 11.1% at 3 years [P = .021]). In contrast, among the non-CR patients, there were no differences between the TBI and non-TBI groups with respect to OS (P = .094), relapse (P = .83), and NRM (P = .27). Our data indicate that outcomes may be more favorable in younger AYA patients than in older AYA patients in non-CR at transplantation, and that outcomes of TBI-based conditioning could be comparable to those of non-TBI-based conditioning for AYA patients.

Trends in survival of leukemia among children, adolescents, and young adults: A population-based study in Osaka, Japan

This study focused on children as well as adolescents and young adults (AYAs) and aimed to examine trends in survival of leukemia over time using population-based cancer registry data from Osaka, Japan. The study subjects comprised 2254 children (0-14 years) and 2,905 AYAs (15-39 years) who were diagnosed with leukemia during 1975-2011. Leukemia was divided into four types: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and other leukemias. We analyzed 5-year overall survival probability (5y-OS), using the Kaplan-Meier method and expressed time trends using the joinpoint regression model. For recently diagnosed (2006-2011) patients, a Cox proportional hazards model was applied to determine predictors of 5y-OS, using age group, gender, and treatment hospital as covariates. Over the 37-year period, 5y-OS greatly improved among both children and AYAs, for each leukemia type. Among AYAs, 5y-OS of ALL improved, especially after 2000 (65% in 2006-2011), when the pediatric regimen was introduced but was still lower than that among children (87% in 2006-2011, P < .001). Survival improvement was most remarkable in CML, and its 5y-OS was over 90% among both children and AYAs after the introduction of molecularly targeted therapy with tyrosine kinase inhibitors. Among patients with recently diagnosed AML, the risk of death was significantly higher for patients treated at nondesignated hospitals than those treated at designated cancer care hospitals. The changes in survival improvement coincided with the introduction of treatment regimens or molecularly targeted therapies. Patient centralization might be one option which would improve survival.

Pediatric hematopoietic cell transplantation: Longitudinal trends in body mass index and outcomes

Pediatric recipients of HCT may have a high susceptibility for overweight and obesity, and obesity may negatively impact post-transplant mortality and survival. This is a single-center retrospective analysis of 297 pediatric patients who received HCT between 2005 and 2018. Patients were classified as UW, NW, OW, or OB based on age-adjusted BMI. A mixed-effects linear regression model controlling for patient, disease, and transplant-related characteristics was used to trend weight longitudinally. Comparisons were made between weight category and post-transplant outcomes. In the pretransplant period, 5.4%, 54.5%, 22.2%, and 17.8% of patients were UW, NW, OW, and OB, respectively. Five years post-transplantation, those numbers were 10.6%, 48.2%, 16.5%, and 24.7%. Overall, BMI increased 0.00094 ± 0.0001 kg/m² each day post-transplant (P < .001), with older individuals demonstrating greater rates of increase. Further, there was a larger BMI increase in patients without TBI compared with those who received TBI (1.29 ± 0.49, P = .008). Rates of acute GVHD, chronic GVHD, and viral infections, in addition to time to platelet and neutrophil engraftment and 5-year survival estimates, were not significantly different based on pretransplant BMI. Overweight and obese individuals had poorer 5-year survival based on 100-day post-transplant BMI (P = .02). Overall, pediatric HCT recipients are at risk of developing obesity, which is associated with decreased survival. Adolescents and young adults demonstrate the highest risk of weight gain, representing a vulnerable population that requires close monitoring, additional interventions, and further research.

Identifying risk factors associated with worse outcomes in adolescents and young adults undergoing hematopoietic stem cell transplantation

BACKGROUND

Adolescents and young adults (AYAs) undergoing allogeneic hematopoietic stem cell transplantation (HSCT) have unique risk factors and poor outcomes when compared to children, but this population has not been well studied. A hematopoietic stem cell transplantation-comorbidity index (HCT-CI) has been developed in adults to help predict outcomes, yet this index does not seem suitable for a younger population. Therefore, we sought to examine the prevalence of various risk factors in AYAs undergoing allogeneic HSCT and determine which factors had the greatest impact on overall survival (OS) and treatment-related mortality (TRM).

PROCEDURES

This was accomplished by retrospectively collecting data on 241 patients who received their first allogeneic HSCT at UCLA between 2005 and 2015. We investigated the effect of multiple predictors using the Cox proportional hazards model and Fine and Gray competing risk model for OS and TRM, respectively.

RESULTS

Our results showed that AYAs undergoing allogeneic HSCT had poor outcomes, with 5-year OS and NRM of 48% and 30%, respectively. We demonstrated that compared to a baseline model, the addition of the HCT-CI did not improve its ability to predict OS, while substituting individual comorbidities, that is, an unweighted comorbidity score, resulted in significant improvement in model performance. The factors associated with inferior outcomes were used to develop an AYA-specific risk score.

CONCLUSIONS

The comorbidities included in the HCT-CI as well as additional risk factors seen in younger populations need to be studied in prospective studies with the goal of validating and refining a risk score specific to AYA patients undergoing allogeneic HSCT.

Acute myelogenous leukemia in adolescents and young adults

The incidence of acute myelogenous leukemia (AML) increases progressively with age. Favorable genetic mutations are most prevalent in children, and unfavorable profiles increase proportionately in adolescents and young adults (AYA) and into later adulthood. Survival rates of AYA have improved over recent decades to 50-60%, but their accrual to clinical trials remains poor. In contrast to AYA with acute lymphoblastic leukemia, the prognostic benefit for AYA with AML enrolled in pediatric compared with adult trials is minor and only seen when different protocols are used. The distinctive needs of AYA, including intensive psychological services, call for their treatment within specialized centers that offer complex supportive care.

Prognostic value of genetic mutations in adolescent and young adults with acute myeloid leukemia

Clinical outcomes and the genetic background of acute myeloid leukemia (AML) in adolescent and young adults (AYAs) are known to differ in younger children and older adults. To clarify the impact of genetic mutations on clinical outcomes of AYAs with AML, we analyzed data from the JPLSG AML-05 and JALSG AML201 studies. AYAs aged 15-39 years (n = 103) were included. FLT3-ITD, KIT, CEBPA, NRAS, KRAS, WT1, MLL-PTD, and NPM1 mutations were analyzed. Overall survival (OS) of the AYAs was 61% and event-free survival was 38% at 3 years. FLT3-ITD (HR 2.10; 95% CI 1.07-4.12; p = 0.031) and NPM1 (HR 0.24; 95% CI 0.06-1.00; p = 0.050) mutations were associated with risk of overall mortality in multivariate analysis. OS was significantly different according to FLT3-ITD and NPM1 mutation status (p = 0.03). Survival was 100% with NPM1 mutations in the absence of FLT3-ITD and 35% (95% CI 14-57%) with FLT3-ITD in the absence of NPM1 mutations. The OS of AYAs, children (n = 413) and older adults (n = 124) of the AML-05 and AML201 participants were significantly different (p < 0.0001). This is the first report to combine clinical and genetic data of AYA AML from the major Japanese pediatric and adult study groups.